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NetBSD/usr.sbin/tcpdchk/tcpdchk.c

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/* $NetBSD: tcpdchk.c,v 1.4 1997/10/17 13:49:49 lukem Exp $ */
/*
* tcpdchk - examine all tcpd access control rules and inetd.conf entries
*
* Usage: tcpdchk [-a] [-d] [-i inet_conf] [-v]
*
* -a: complain about implicit "allow" at end of rule.
*
* -d: rules in current directory.
*
* -i: location of inetd.conf file.
*
* -v: show all rules.
*
* Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
*/
#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#) tcpdchk.c 1.7 96/02/11 17:01:34";
#else
__RCSID("$NetBSD: tcpdchk.c,v 1.4 1997/10/17 13:49:49 lukem Exp $");
#endif
#endif
/* System libraries. */
#include <sys/types.h>
#include <sys/stat.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <syslog.h>
#include <setjmp.h>
#include <errno.h>
#include <netdb.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#ifndef INADDR_NONE
#define INADDR_NONE (-1) /* XXX should be 0xffffffff */
#endif
#ifndef S_ISDIR
#define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
#endif
/* Application-specific. */
#include "tcpd.h"
#include "inetcf.h"
#include "scaffold.h"
/*
* Stolen from hosts_access.c...
*/
static char sep[] = ", \t\n";
#define BUFLEN 2048
int resident = 0;
int hosts_access_verbose = 0;
char *hosts_allow_table = HOSTS_ALLOW;
char *hosts_deny_table = HOSTS_DENY;
extern jmp_buf tcpd_buf;
/*
* Local stuff.
*/
static void usage __P((void));
static void parse_table __P((char *, struct request_info *));
static void print_list __P((char *, char *));
static void check_daemon_list __P((char *));
static void check_client_list __P((char *));
static void check_daemon __P((char *));
static void check_user __P((char *));
static int check_host __P((char *));
static int reserved_name __P((char *));
int main __P((int, char **));
#define PERMIT 1
#define DENY 0
#define YES 1
#define NO 0
static int defl_verdict;
static char *myname;
static int allow_check;
static char *inetcf;
int main(argc, argv)
int argc;
char **argv;
{
struct request_info request;
struct stat st;
int c;
myname = argv[0];
/*
* Parse the JCL.
*/
while ((c = getopt(argc, argv, "adi:v")) != -1) {
switch (c) {
case 'a':
allow_check = 1;
break;
case 'd':
hosts_allow_table = "hosts.allow";
hosts_deny_table = "hosts.deny";
break;
case 'i':
inetcf = optarg;
break;
case 'v':
hosts_access_verbose++;
break;
default:
usage();
/* NOTREACHED */
}
}
if (argc != optind)
usage();
/*
* When confusion really strikes...
*/
if (check_path(REAL_DAEMON_DIR, &st) < 0) {
tcpd_warn("REAL_DAEMON_DIR %s: %m", REAL_DAEMON_DIR);
} else if (!S_ISDIR(st.st_mode)) {
tcpd_warn("REAL_DAEMON_DIR %s is not a directory", REAL_DAEMON_DIR);
}
/*
* Process the inet configuration file (or its moral equivalent). This
* information is used later to find references in hosts.allow/deny to
* unwrapped services, and other possible problems.
*/
inetcf = inet_cfg(inetcf);
if (hosts_access_verbose)
printf("Using network configuration file: %s\n", inetcf);
/*
* These are not run from inetd but may have built-in access control.
*/
inet_set("portmap", WR_NOT);
inet_set("rpcbind", WR_NOT);
/*
* Check accessibility of access control files.
*/
(void) check_path(hosts_allow_table, &st);
(void) check_path(hosts_deny_table, &st);
/*
* Fake up an arbitrary service request.
*/
request_init(&request,
RQ_DAEMON, "daemon_name",
RQ_SERVER_NAME, "server_hostname",
RQ_SERVER_ADDR, "server_addr",
RQ_USER, "user_name",
RQ_CLIENT_NAME, "client_hostname",
RQ_CLIENT_ADDR, "client_addr",
RQ_FILE, 1,
0);
/*
* Examine all access-control rules.
*/
defl_verdict = PERMIT;
parse_table(hosts_allow_table, &request);
defl_verdict = DENY;
parse_table(hosts_deny_table, &request);
return (0);
}
/* usage - explain */
static void usage()
{
fprintf(stderr, "usage: %s [-a] [-d] [-i inet_conf] [-v]\n", myname);
fprintf(stderr, " -a: report rules with implicit \"ALLOW\" at end\n");
fprintf(stderr, " -d: use allow/deny files in current directory\n");
fprintf(stderr, " -i: location of inetd.conf file\n");
fprintf(stderr, " -v: list all rules\n");
exit(1);
}
/* parse_table - like table_match(), but examines _all_ entries */
static void parse_table(table, request)
char *table;
struct request_info *request;
{
FILE *fp;
int real_verdict;
char sv_list[BUFLEN]; /* becomes list of daemons */
char *cl_list; /* becomes list of requests */
char *sh_cmd; /* becomes optional shell command */
int verdict;
struct tcpd_context saved_context;
#ifdef __GNUC__
/* XXX hack to avoid gcc warnings */
(void) &real_verdict;
(void) &saved_context;
#endif
saved_context = tcpd_context; /* stupid compilers */
if ((fp = fopen(table, "r")) != NULL) {
tcpd_context.file = table;
tcpd_context.line = 0;
while (xgets(sv_list, sizeof(sv_list), fp)) {
if (sv_list[strlen(sv_list) - 1] != '\n') {
tcpd_warn("missing newline or line too long");
continue;
}
if (sv_list[0] == '#' || sv_list[strspn(sv_list, " \t\r\n")] == 0)
continue;
if ((cl_list = split_at(sv_list, ':')) == 0) {
tcpd_warn("missing \":\" separator");
continue;
}
sh_cmd = split_at(cl_list, ':');
if (hosts_access_verbose)
printf("\n>>> Rule %s line %d:\n",
tcpd_context.file, tcpd_context.line);
if (hosts_access_verbose)
print_list("daemons: ", sv_list);
check_daemon_list(sv_list);
if (hosts_access_verbose)
print_list("clients: ", cl_list);
check_client_list(cl_list);
#ifdef PROCESS_OPTIONS
real_verdict = defl_verdict;
if (sh_cmd) {
if ((verdict = setjmp(tcpd_buf)) != 0) {
real_verdict = (verdict == AC_PERMIT);
} else {
dry_run = 1;
process_options(sh_cmd, request);
if (dry_run == 1 && real_verdict && allow_check)
tcpd_warn("implicit \"allow\" at end of rule");
}
} else if (defl_verdict && allow_check) {
tcpd_warn("implicit \"allow\" at end of rule");
}
if (hosts_access_verbose)
printf("access: %s\n", real_verdict ? "granted" : "denied");
#else
if (sh_cmd)
shell_cmd(percent_x(buf, sizeof(buf), sh_cmd, request));
if (hosts_access_verbose)
printf("access: %s\n", defl_verdict ? "granted" : "denied");
#endif
}
(void) fclose(fp);
} else if (errno != ENOENT) {
tcpd_warn("cannot open %s: %m", table);
}
tcpd_context = saved_context;
}
/* print_list - pretty-print a list */
static void print_list(title, list)
char *title;
char *list;
{
char buf[BUFLEN];
char *cp;
char *next;
fputs(title, stdout);
strcpy(buf, list);
for (cp = strtok(buf, sep); cp != 0; cp = next) {
fputs(cp, stdout);
next = strtok((char *) 0, sep);
if (next != 0)
fputs(" ", stdout);
}
fputs("\n", stdout);
}
/* check_daemon_list - criticize daemon list */
static void check_daemon_list(list)
char *list;
{
char buf[BUFLEN];
char *cp;
char *host;
int daemons = 0;
strcpy(buf, list);
for (cp = strtok(buf, sep); cp != 0; cp = strtok((char *) 0, sep)) {
if (STR_EQ(cp, "EXCEPT")) {
daemons = 0;
} else {
daemons++;
if ((host = split_at(cp + 1, '@')) != 0 && check_host(host) > 1) {
tcpd_warn("host %s has more than one address", host);
tcpd_warn("(consider using an address instead)");
}
check_daemon(cp);
}
}
if (daemons == 0)
tcpd_warn("daemon list is empty or ends in EXCEPT");
}
/* check_client_list - criticize client list */
static void check_client_list(list)
char *list;
{
char buf[BUFLEN];
char *cp;
char *host;
int clients = 0;
strcpy(buf, list);
for (cp = strtok(buf, sep); cp != 0; cp = strtok((char *) 0, sep)) {
if (STR_EQ(cp, "EXCEPT")) {
clients = 0;
} else {
clients++;
if ((host = split_at(cp + 1, '@')) != NULL) { /* user@host */
check_user(cp);
check_host(host);
} else {
check_host(cp);
}
}
}
if (clients == 0)
tcpd_warn("client list is empty or ends in EXCEPT");
}
/* check_daemon - criticize daemon pattern */
static void check_daemon(pat)
char *pat;
{
if (pat[0] == '@') {
tcpd_warn("%s: daemon name begins with \"@\"", pat);
} else if (pat[0] == '.') {
tcpd_warn("%s: daemon name begins with dot", pat);
} else if (pat[strlen(pat) - 1] == '.') {
tcpd_warn("%s: daemon name ends in dot", pat);
} else if (STR_EQ(pat, "ALL") || STR_EQ(pat, unknown)) {
/* void */ ;
} else if (STR_EQ(pat, "FAIL")) { /* obsolete */
tcpd_warn("FAIL is no longer recognized");
tcpd_warn("(use EXCEPT or DENY instead)");
} else if (reserved_name(pat)) {
tcpd_warn("%s: daemon name may be reserved word", pat);
} else {
switch (inet_get(pat)) {
case WR_UNKNOWN:
tcpd_warn("%s: no such process name in %s", pat, inetcf);
inet_set(pat, WR_YES); /* shut up next time */
break;
case WR_NOT:
tcpd_warn("%s: service possibly not wrapped", pat);
inet_set(pat, WR_YES);
break;
}
}
}
/* check_user - criticize user pattern */
static void check_user(pat)
char *pat;
{
if (pat[0] == '@') { /* @netgroup */
tcpd_warn("%s: user name begins with \"@\"", pat);
} else if (pat[0] == '.') {
tcpd_warn("%s: user name begins with dot", pat);
} else if (pat[strlen(pat) - 1] == '.') {
tcpd_warn("%s: user name ends in dot", pat);
} else if (STR_EQ(pat, "ALL") || STR_EQ(pat, unknown)
|| STR_EQ(pat, "KNOWN")) {
/* void */ ;
} else if (STR_EQ(pat, "FAIL")) { /* obsolete */
tcpd_warn("FAIL is no longer recognized");
tcpd_warn("(use EXCEPT or DENY instead)");
} else if (reserved_name(pat)) {
tcpd_warn("%s: user name may be reserved word", pat);
}
}
/* check_host - criticize host pattern */
static int check_host(pat)
char *pat;
{
char *mask;
int addr_count = 1;
if (pat[0] == '@') { /* @netgroup */
#ifdef NO_NETGRENT
/* SCO has no *netgrent() support */
#else
#ifdef NETGROUP
char *machinep;
char *userp;
char *domainp;
setnetgrent(pat + 1);
if (getnetgrent(&machinep, &userp, &domainp) == 0)
tcpd_warn("%s: unknown or empty netgroup", pat + 1);
endnetgrent();
#else
tcpd_warn("netgroup support disabled");
#endif
#endif
} else if ((mask = split_at(pat, '/')) != NULL) { /* network/netmask */
if (dot_quad_addr(pat) == INADDR_NONE
|| dot_quad_addr(mask) == INADDR_NONE)
tcpd_warn("%s/%s: bad net/mask pattern", pat, mask);
} else if (STR_EQ(pat, "FAIL")) { /* obsolete */
tcpd_warn("FAIL is no longer recognized");
tcpd_warn("(use EXCEPT or DENY instead)");
} else if (reserved_name(pat)) { /* other reserved */
/* void */ ;
} else if (NOT_INADDR(pat)) { /* internet name */
if (pat[strlen(pat) - 1] == '.') {
tcpd_warn("%s: domain or host name ends in dot", pat);
} else if (pat[0] != '.') {
addr_count = check_dns(pat);
}
} else { /* numeric form */
if (STR_EQ(pat, "0.0.0.0") || STR_EQ(pat, "255.255.255.255")) {
/* void */ ;
} else if (pat[0] == '.') {
tcpd_warn("%s: network number begins with dot", pat);
} else if (pat[strlen(pat) - 1] != '.') {
check_dns(pat);
}
}
return (addr_count);
}
/* reserved_name - determine if name is reserved */
static int reserved_name(pat)
char *pat;
{
return (STR_EQ(pat, unknown)
|| STR_EQ(pat, "KNOWN")
|| STR_EQ(pat, paranoid)
|| STR_EQ(pat, "ALL")
|| STR_EQ(pat, "LOCAL"));
}
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